Revert "Run all available tests if there are no pending --failed tests"

This reverts commit ae48325.

Author: josevalim

lib/mix/lib/mix/tasks/test.ex

@@ -116,8 +116,7 @@ defmodule Mix.Tasks.Test do
     * `--export-coverage` - the name of the file to export coverage results to.
       Only has an effect when used with `--cover`
 
-    * `--failed` - runs only tests that failed the last time they ran.
-      If there are no pending --failed tests, `mix test` will run all available tests
+    * `--failed` - runs only tests that failed the last time they ran
 
     * `--force` - forces compilation regardless of modification times
 
@@ -702,13 +701,7 @@ defmodule Mix.Tasks.Test do
       end
 
       {allowed_files, failed_ids} = ExUnit.Filters.failure_info(manifest_file)
-
-      if MapSet.size(failed_ids) == 0 do
-        Mix.shell().info("No pending --failed tests, re-running all available tests...")
-        {opts, nil}
-      else
-        {Keyword.put(opts, :only_test_ids, failed_ids), allowed_files}
-      end
+      {Keyword.put(opts, :only_test_ids, failed_ids), allowed_files}
     else
       {opts, nil}
     end

lib/mix/test/mix/tasks/test_test.exs

@@ -214,13 +214,8 @@ defmodule Mix.Tasks.TestTest do
         System.put_env("PASS_FAILING_TESTS", "true")
         assert mix(["test", "--failed"]) =~ "2 tests, 0 failures"
 
-        # All tests should be run if we try it again with no failing tests.
-        # This prevents `mix test --failed` from passing in cases where
-        # `mix test` had a compilation error before having failing tests.
-        # It also provides a better workflow as you can always run with --failed.
-        output = mix(["test", "--failed"])
-        assert output =~ "No pending --failed tests, re-running all available tests..."
-        assert output =~ "4 tests, 0 failures"
+        # Nothing should get run if we try it again since everything is passing.
+        assert mix(["test", "--failed"]) =~ "There are no tests to run"
 
         # `--failed` and `--stale` cannot be combined
         output = mix(["test", "--failed", "--stale"])